Gas spring arrangements of this kind are used especially to damp the pivotal movement of the back rest support, or of the backrest or, possibly combined with this, of the seat. To permit the user of such office chairs to either fix the inclination of the backrest or the seat in a desired position or to maintain the backrest of the seat pivotable, so that they can follow the movements of the body, it is known to provide releasable adjustment means to arrest the pivotal movement. Such adjustment means, when used with longitudinally adjustable gas springs, can either act directly upon the gas spring or it is possible to provide a separate mechanical adjustment means in addition to the gas spring. Such mechanical adjustment means have the advantage that more cost-effective gas springs can be used.
Two competing demands on such gas spring arrangements result from this particular problem. On the one hand, the adjustment means should make possible an absolutely secure fixing of, for instance, the seat or the backrest, in a desired position of inclination in spite of the comparatively high torque which occurs. On the other hand, the adjustment means should be operable with ease to assure trouble-free operation. In addition, care must be taken that the adjustment means in the released position does not hinder the pivoting movement, but only damps it by means of the gas spring.